The number 8180
8180 is a composite number with 12 divisors. Its prime factorisation is × 5 × 409. Divisors (12): 1, 2, 4, 5, 10, 20, 409, 818, 1636, 2045, 4090, 8180.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 8180: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
8180 is composite. Its prime factorisation is
- 3
The divisors add up to 17220; without 8180 itself that is 9040, so 8180 is abundant (9040 is more than 8180). Euler's totient φ(8180) = 3264 numbers up to 8180 share no factor with it.
- 4
The digits of 8180 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 65 steps to reach 1.
LaTeX source of the formulas on this page
\[ 8180 = 2^{2} \times 5 \times 409 \]8180 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 17220 |
| Euler totient φ(n) | 3264 |
| Square | 66912400 |
| Cube | 547343432000 |
| Square root | 90.443352 (= 2√2045) |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 65 |
| Scientific notation | 8.18 × |
8180 in other forms
| Form | Value |
|---|---|
| In words | eight thousand one hundred and eighty |
| Binary (base 2) | 1111111110100 |
| Octal (base 8) | 17764 |
| Hexadecimal (base 16) | 1FF4 |
| Base 3 | 102012222 |
| As time | 8180 seconds = 2 h 16 min 20 s |
Is 8180 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (8180 ÷ 2 = 4090) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (8180 ÷ 4 = 2045) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (8180 ÷ 5 = 1636) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | A number is divisible by 7 if double the last digit and subtract it from the rest: the result is a multiple of 7. |
| 8 | No (remainder 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (8180 ÷ 10 = 818) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 8180 a prime number?
No. 8180 = × 5 × 409, so it is divisible by 2.
What are the factors of 8180?
1, 2, 4, 5, 10, 20, 409, 818, 1636, 2045, 4090, 8180.
What is 8180 in binary?
1111111110100 (hexadecimal 1FF4, octal 17764).
What is the square root of 8180?
About 90.4434, exactly 2√2045.
Is 8180 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 8180?
8180 is a happy number: repeatedly adding the squares of its digits reaches 1.